JWSS - Journal of Water and Soil Science

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Floodwater Spreading (FS) plays an effective role in improving soil fertility, ground water recharge, vegetation cover, and desertification control. The soil fertility might increase as a result of a suitable suspended sediment material transferred to the downstream by flood events. To define a relevant FS method which increases the efficiency of the FS projects, it is necessary to study the quality and quantity of transported sediment material, spatially and temporarily. In this research, this subject was investigated by taking soil samples throughout 13 FS stations for physical and chemical analysis over 5 years. Within each of the 13 selected stations in the three first flooded dikes, soil sampling was carried out using random-systematic method. The total Nitrogen, absorbed Phosphorous and Potassium, and Organic Carbon of each sample were analyzed. Because of the abnormality of data, nonparametric test was adopted to compare means. All stations were classified into three groups using cluster analysis method. Based on the results, the variations of fertility factors are irregular between the dikes and amongst years. This could have been affected by several factors such as the quality and quantity of diverted flood, the characteristic of FS sites, and irregularity of sediment material deposited on the sites. Despite the low quality of soil fertility prior to the construction of these stations, in general, FS has a considerable role in improving the soil fertility. However, desirable objectives may be achieved in long term through occurrence of diverse flood events and suitable maintenance of the stations.

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Microbial transport in soil is critical in different ways, especially in groundwater contamination and bioremediation of groundwater or soil. The main objectives of this research were quantitative study of bacterial transport and deposition under saturated conditions in calcareous soils. A series of column leaching experiments were conducted. Breakthrough curves (BTCs) of Pseudomonas fluorescens and Cl- were measured. After leaching experiment the bacteria was measured in difference layers of the soil columns. The HYDRUS-1D one- and two-site kinetic attachment-detachment models were used to fit and predict transport and deposition of bacteria in soil columns experiments. The results indicated that two-site kinetic model leads to better prediction breakthrough curves and bacteria retention in the calcareous soil in comparison with one-site kinetic model. Interaction with kinetic site 1 was characterized by relatively fast attachment and slow detachment, whereas attachment to and detachment from kinetic site 2 was fast. Fast attachment and slow detachment of site 1 was attributed to soil calcium carbonate that has favorable attachment site for bacteria. The detachment rate was less than 0.01 of the attachment rate, indicating irreversible attachment of bacteria. Most of the cells were retained close to the soil column inlet, and the rate of deposition decreased with depth. Microbial reduction rate for the soil was 4.02-4.88 log m-1. High reduction rate of bacteria was also attributed to soil calcium carbonate that has favorable attachment site for bacteria.

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The effects of soil intrinsic properties on soil structural stability were evaluated. Soil samples (33 series) with wide ranges of properties and structural stability were collected from Hamadan province. Two structural stability indices were used: mean weight diameter (MWD) using Yoder method and De Leenheer-De Boodt index (DDI). Wetting pre-treatments (fast wetting to saturation and slow wetting to a matric suction of 30 kPa) were applied before wetting. Linear and multiple regression relations of MWD and DDI with the soil intrinsic properties (organic matter, clay, fine clay, silt, sand, calcium carbonate, EC and pH) were assessed. Results showed that organic matter had the highest impact on the two mentioned indices. Following organic matter, clay, fine clay and calcium carbonate were ranked respectively one after another. Fast wetting caused a higher aggregate break-down, due to its destructive energy, air entrapment, and non-uniform swelling of the soil whereas slow wetting exhibited better differentiation of soils with low structural stability. The findings of this research demonstrated high agreement (R2>75%) between the MWD and DDI, recommended both to be used for evaluating of the aggregate stability in Hamedan province

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Among the environmental pollutants, heavy metals according to their irresolvable and physiological effects on living organisms at low concentrations, are of special importance These elements due to low mobility are gradually accumulated in soil Being accumulated in soil, they eventually enter the food chains and threaten human health and other creatures Therefore, studying concentration distribution of heavy metals for soil pollution monitoring and maintaining environmental quality is essential In this study we investigated the effect of agricultural land use and geology on the concentration of heavy metals contamination of soil and spatial distribution map, using collected data, GIS and GeostatisticsUsing systematic stratified random sampling, 135 surface soil samples( 0-20 cm) from an area of 7262 sq km area and we measured total concentration of elements Nickel, Chromium and Cobalt and soil characteristics including pH, organic matter and texture. The mean value of elements concentrations turned out to be Cr: 88.9+22.7 Co: 17.6+3.5 Ni 63.1+17.7 mg per kg and the mean acidity is 7.8 which in the area is an indication …… property. Formetal concentrations interpolation procedures, Geostatistics was used. By the aid of spatial correlation analysis, appropriate interpolation method using functions mean absolute error and bias average error were selected. Interpolation map concentrations of heavy metals Chromium, Cobalt and Nickel with ordinary kriging method and the exponential model were developed Interpolation map analysis of heavy metals by the aid of geological and land use maps show that the distribution of the elements Chromium, Cobalt and Nickel are consistent with the geology classes However, they did not match the agriculture pattern Findings of this study in the area give us appropriate information about the concentration distribution of heavy metals Chromium, Cobalt and Nickel which can be used in monitoring and evaluation processes of heavy metals pollution in agricultural lands area. But on the other hand sampling in the areas far away from human effects, showed that the heavy metals concentration is naturally high.

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Application of compost and compost leachate as organic fertilizers can improve plant growth, nutrients uptake and increase phytoavailability of nutrients in soil. A factorial experiment (4×4×2) was conducted in a completely randomized design to evaluate the effect of compost and compost leachate on growth and chemical composition of barley and bioavailability of some nutrients in calcareous clay loam soil and sandy soil under greenhouse conditions. Treatments consisted of four levels of compost (0, 15, 30, and 60 g kg-1), four levels of compost leachate (0, 10, 20, and 40 g kg-1), and two culture mediums (clay loam soil and sandy soil) with three replicates. Results indicated that application of compost and compost leachate significantly increased barley shoot dry matter, the number of tillers, spikes and grain yield in clay loam soil and sandy soil. The maximum barley shoots dry matter and numbers of tillers in both culture mediums were obtained at the highest level of compost or compost leachate, and the maximum number of spikes and grain yield were obtained at the lowest level of compost or compost leachate. Application of compost in clay loam soil and sandy soil increased shoot and root concentrations of nitrogen (N), phosphorus (P), Iron (Fe), manganese (Mn), zinc (Zn) and copper (Cu). However, addition of compost leachate only increased shoot concentrations of Fe and P. Increasing compost levels increased post harvest concentrations of NO3- N, P, Fe, Mn, Zn, Cu and also electrical conductivity and organic matter content of clay loam soil and sandy soil. Addition of compost leachate significantly increased concentrations of Fe, Zn, Cu and also electrical conductivity and organic matter content of both culture mediums. In both culture mediums and both compost and compost leachate treatments, post harvest concentrations of micronutrients were above critical levels. Therefore, addition of these nutrients is not required for the next cultivation. Generally, compost and compost leachate are appropriate organic fertilizers for barley production however, high salinity level in compost leachate, the rate and frequency of leachate application, particularly in sand, needs intensive control and monitoring. Prior to any fertilizer recommendation, the results of this study need to be verified under field conditions, as well.

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As the first event in soil erosion, rain splash erosion causes movement of soil fragments. Splash is an important process in interrill erosion. The amount of soil particles detached from the surface is associated with soil and rain characteristics and may be affected by rainfall erosivity and soil erodibility. Therefore, in this study, splash erosion rate and its relation with some soil properties were studied. 120 soil samples were collected from three adjacent land uses including forest, rangeland and agriculture in two depths of 0-10 and10-20 cm in Kasilian Watershed. Soil samples were investigated under the experimental condition using splash cup and rainfall simulator. Results showed no significant differences between splash erosion in different land uses. Cultivated and rangeland soils were found to show a significantly lower organic matter (OM) by 59.93% and 33.62% in depth (0-10cm) and 33.33% and 25.59% in depth (10-20cm), respectively. We also found significance positive correlation between percent of silt and splash erosion rate in agriculture (r=0.69, p=0.018) and significance negative correlation between soil organic matter and splash erosion rate in rangeland (r=0.767, p=0.001) and significance positive correlation between K-USLE and splash erosion rate in agriculture (r=0.00, p=0.758).

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Soil water characteristic curve shows the relationship between soil water content and matric suction, which has an important role in water movement in the soil. The measurement of this curve is expensive and time-consuming in laboratory therefore, many methods have been proposed for its estimation including pedotransfer functions. By using the pedotransfer functions, soil water characteristic curve can be estimated based on other easily measured soil physicochemical properties. Parametric pedotransfer functions have been offered for parameters of the existing soil water characteristic curve models. In this study, 12 internal and external parametric pedotransfer functions of Brooks and Corey, Campbell and van Genuchten models were used and evaluated for 30 top soil samples in Fars province. To this end, the soil water characteristic curve and other necessary soil properties were measured, and then all soils according to the texture were divided into three groups of fine, medium and course textures. The results showed that the parametric pedotransfer functions of van Genuchten model were better than the other models, beacause of the better fit of this model to the measured data. Also, the results demonstrated that the parametric pedotransfer functions of Wosten et al. were the most appropriate method for estimating the soil water characteristic curve for the selected soils in Fars province, and that internal pedotransfer functions were not appropriate

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In order to investigate the effect of vermicompost on physical and chemical properties of soil, an experiment was carried out in split plot based on complete randomized block design in three replications in Sari Agricultural Sciences and Natural Resources University. The physical and chemical properties of soil included bulk density, particle density, total porosity, water holding capacity, field capacity, permanent wilting point, available water capacity, pH, organic carbon and electrical conductivity in soil. Six levels of fertilizer treatments (T1= control, T2= chemical fertilizer, T3= 20 tons vermicompost + 1/2 T2, T4 = 20 tons / hac vermicompost + 1/2 T2 , T5= 40 tons vermicompost + 1/2 T2 and T6= 40 tons / hac vermicompost) and three levels of application years, one year of fertilization (1385), two consecutive years of fertilization (1385 and 1386) and three consecutive years of fertilization (1385, 1386, 1387). The results of the study showed that the application of these treatments in soil were significantly effective in increasing the total porosity, water holding capacity, field capacity, permanent wilting point, available water capacity, organic carbon electrical conductivity and in decreasing the bulk density, particle density and pH compared to control. In Contrast years of consumption of fertilizer did not have any significant effect on the physical properties of the soil except for FC, PWP, AWC, pH, OC and EC. The interaction between years of consumption of fertilizers were significantly different only in particle density and field capacity.

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In recent years, simulatiom modelling of yield has been the focus of attention for many researchers. Because, while reducing adminestrative costs, it can easily provide simulation models of different situations. In this study, while a subroutine on simulation of canola was added to CRPSM model, effect of different water treatments on canola was also investigated. In this research, canola (Talaye) under 5 irrigation treatments (full irrigation treatment during the growing period, water stress treatment at the spring re-growth stage, the flowering stage and pod formation, the grain formation stage and dry land treatment) was sown in complete randomized block designs at the college of Agriculture, Shiraz University during 2007-2008, and then the model was calibrated based on available information (soil-location -plant-water). Review of statistical indicators between simulated and measured yield show high accuracy in the estimation of crop yield (R2=0.98) and soil water content. The result of model validation with independent data series also showed that the result of soil water content is desirable except in dry treatment, and the corrolation coeficient between simulated and measured crop yield (R2=0.98) was acceptable.

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Contamination of agricultural soils by heavy metals is a serious threat from both agricultural and environmental standpoints. Among heavy metals, cadmium (Cd) toxicity for humans and plants is of great concern due to its high mobility and phytoavailability in soil even at low concentrations. Opposite to Cd, Phosphorus (P) is an essential nutrient for plant growth. A greenhouse experiment was carried out in a completely randomized design to examine the influence of Cd, P and their interaction on the growth and chemical composition of spinach grown on a calcareous soil. Treatments consisted of four Cd levels (5, 10, 20 and 40 mg/kg soil as cadmium sulfate) and four P levels (0, 20, 40 and 80 mg/kg soil as mono-calcium phosphate) in three replicates. The results indicated that 40 mg Cd significantly decreased spinach dry weight by 47% but P application decreased detrimental effect of Cd on spinach dry weight. Also, phosphorus application significantly decreased Cd concentration in spinach aerial parts by 78%. Increasing Cd levels increased concentration of this element in spinach shoots. Addition of 40 mg Cd decreased P concentration by 21.5% in aerial parts. Zinc (Zn), manganese (Mn), calcium (Ca), and nitrogen (N) concentration significantly decreased with P application but increased concentration of sodium (Na). Cadmium application decreased Zn concentration but increased Ca, Na and N concentrations in spinach. Our tentative conclusion is that P application in P-deficient soils is probably effective in decreasing Cd concentration and the detrimental effect of Cd on spinach growth, indicating a negative interaction between these elements. Prior to any fertilizer recommendation, the results of this experiment should be verified under field conditions

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Waste tire rubbers are considered one of the environment pollutants. Increased production of these pollutants has led to more serious consideration of ways to reduce the harms caused by their accumulation in the environment. Therefore, the effects of incorporation of waste rubber crushed particles in two sizes of 1-2 and 3-5 mm and the amounts of 0, 5, 10 and 20 Mg ha-1 in a calcareous soil (0-30 cm depth) on some chemical properties of soil was investigated in Isfahan University of Technology research field (Lavark). This experiment was performed using seven treatments along with a non amended control treatment in a randomized complete block design with three replications in 1387. Eight months after incorporation, soil samples were collected for laboratory analyses. Results of ANOVA tables show that soil pH, electrical conductivity, percentage of total nitrogen and DTPA-extractable concentrations of cadmium, lead, copper and iron were not significantly affected by application of rubber particles. Incorporation of rubber particles into the soil significantly increased soil organic carbon and carbon to nitrogen. Increases in the DTPA-extractable Zn in soils treated with 10 and 20 Mg ha rubber particles in fine and coarse sizes were significant in comparison with the control soil. DTPA-extractable Zn content in the soil treated with 10 and 20 Mg ha 3-5 mm waste tire rubbers particles was about two and three times higher than that in the control treatment, respectively. The results of this study showed that in short-time, incorporation of crushed tire rubbers particles had no significant effect on most chemical properties of the soil but increased the available Zn content. In this regard, further studies to monitor the effects of adding waste rubber crushed particles on organic matter mineralization, plant toxicity and physical properties of soil in long-term are recommended.

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In agriculture, cow manures are used to enhance soil fertility and productivity. Escherichia coli is the most common fecal coliform in cow manure and considered as an index for microbial contamination of groundwater resources. The objective of this study was to investigate the transport of Escherichia coli (released from cow manure) through the field soil. Lysimeters (with internal diameter of 20.5 and height of 50 cm) were inserted into an in situ clay loam soil. Unsaturated soil water flow was controlled at an inlet matric potential of –5 cm using a tension infiltrometer. When the steady-state flow was established, air-dried fresh cow manure was applied on the lysimeters at a rate of 10 Mg ha-1 (dry basis) and the soil-manure leaching started. Soil solution was sampled at 1, 2, 4, 6, 12 and 24 h after leaching initiation using plastic samplers installed at depths of 20 and 40 cm. Concentrations of Escherichia coli in the soil solution (C) and the influent (C0) were measured using the plate count method. Impacts of soil depth, sampling time, and their interaction on C and C/C0 were significant (P<0.01). In all leaching times, relative adsorption index (SR) was lower when both soil layers were considered and the filtration increased with soil depth. When the concentration was corrected for the second layer (i.e. 20–40 cm), the SR values in this layer were considerable and greater than those in the first layer at 4 and 6 h. The influence of surface layer was substantial in bacterial filtration however, the preferential flows especially in the initial leaching times resulted in bacterial movement towards the second layer. Temperature drop reduced bacteria release from the manure, increased viscosity of the flowing water, and consequently diminished significantly the bacteria concentration in the soil solution at 24 h. Overall, it was found that similar to surface layer, subsurface layer might have great role in bacterial filtration due to its higher clay and carbonate contents

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The application of herbicides as organic chemical compounds to control pest and weeds may affect the population and activity of microorganisms, and this may have an influence on biochemical processes that are important for soil fertility and plant growth. The primary objective of this study was to evaluate different loading rates of eradican (EPTC) on soil microbial biomass C and N, microbial biomass C/N ratio and the activities of urease and arylsulphatase under field conditions. In this experiment, loading rates of 6 and 9 L ha-1 eradican were applied to a calcareous soil cultivated with corn (Zea mays L.) and left uncultivated using split-plots arranged in a completely randomized block design with three replications. The experiment was conducted in the Kabootarabad’s Agricultural Research Center, Isfahan. Soil microbial biomass C and N were determined at 30th and 90th days after the onset of experiment and the activities of urease and arylsulphatase were assayed at 30th, 60th and 90th days. Results showed that in soils cultivated with corn microbial biomass C increased with increasing eradican levels and in both cultivated and uncultivated soils microbial biomass N and microbial biomass C/N ratios were increased over the control. At 30th day, urease activity at 6 L ha-1 level reduced, while at 9 L ha-1 level it increased compared with the control soils. At 60 day, there was no significant difference in the urease activity between the treatments. At 90th day, the activity of urease showed slight fluctuations. There was a reduction in arylsulphatase activity of the cultivated soils by increasing the loading rates of eradican during the experiment, and in uncultivated soils no trend was observed. Briefly, the use of eradican can cause either reduced or increased microbial biomass sizes and enzyme activities in calcareous soils These changes, however, depend largely upon the application rate of eradican, time elapsed since eradican application (i.e., sampling date) and the presence or absence of plant

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Direct measurement of soil unsaturated hydraulic conductivity (K(h) or K(θ)) is difficult and time-consuming, and often in many applied models, predicting hydraulic conductivity is carried out according to measurements of soil retention curve and saturated hydraulic conductivity (Ks). However, using KS as a matching point in many procedures may result in over-estimation of unsaturated hydraulic conductivity in dry regions. Therefore, the unsaturated hydraulic conductivity at inflection point of retention curve (Ki) and Ks was used as a matching point to predict K(h). For measurement of K(h), 30 soil samples were collected based on variety of soil texture (8 texture classes from sandy to clay) and other chemical and physical properties. In addition to Ks, K(θ) values of undisturbed samples were measured using multi-step outflow method at matric suctions of 0.1, 0.2, 0.3, 0.5 0.7, 1 bar and inflection point of retention curve by using hanging water column and pressure plate. Then, the measured K(h), and water diffusivity (D(θ)) values were compared to the predicted values of van Genuchten and Brooks and Corey models (with Mualem and Burdine constraint). The results showed that for 80% of the samples, the van Genuchten–Mualem model with Ki was the best model for predicting K(h) (i.e. using Ki as a matching point in the van Genuchten–Mualem model resulted in best fitting to measured data). Also, in 6.7 % of samples (two sandy clay samples), Brooks and Corey-Mualem model with Ki and in 13.3 % soil samples (2 silty clay and 2 silty clay loam samples), van Genouchten–Mualem model had a best fitting to K(h) measured data. Furthermore, in 20 % samples (4 clay loam, and 2 silt loam textures), the accuracy and efficiency of van Genuchten–Mualem with Ki and van Genuchten–Mualem models in predicting K(h) were almost similar. According to t-Student test, the mean of RMSE and GSDER of van Genuchten–Mualem model with Ki was significantly less than van Genuchten–Mualem model at P < 0.01. In 90 percent of samples, van Genuchten-Mualem and Brooks and Corey-Burdine theory had the best fitting to the measured data of water diffusivity, but in some cases van Genuchten-Burdine model with Ki was the best model for predicting D(θ).

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Mountainous landscapes in Central Zagros are mainly used as grazing rangelands to feed animals and are heavily degraded. Overgrazing may impose a negative effect on rangeland productivity and sustainability through significant changes in soil properties. Soil nitrogen (N) mineralization is one of the key biological processes that might be affected by biotic and abiotic factors including range grazing regime or intensity. The primary objective of this study was to assess the effects of rangeland management (grazing and ungrazing regimes) on soil N mineralization in natural rangelands of Chaharmahal VA Bakhtiyari province. Three range management regimes including a) long-term ungrazed, b) controlled grazed and c) freely- (over)-grazed plots in a close vicinity were selected in three regions consisting of SabzKouh (protected from grazing for 18 years), Boroujen (protected from grazing for 23 years) and Sheida (protected from grazing for 2 years), and soil samples were collected from 0-15 cm depth for some physical and chemical properties. Soil N mineralization was measured under standard laboratory conditions. At SabzKouh, the effect of range management on the cumulative N mineralization and the proportion of N mineralized (%) was significant (P<0.05) and ungrazing regime resulted in 89% and 96% increases in soil N mineralization in ungrazed rangelands compared with controlled grazed and freely- grazed rangelands, respectively. Similarly, soil N mineralization was significantly greater (P<0.05) in ungrazed rangelands (3.3- to 3.5-folds) than in controlled grazed and freely-grazed rangelands at Boroujen site. However, at Sheida site with short-term ungrazing period and cropping history there were no significant and considerable differences in soil N mineralization among the three grazing regimes. Briefly, degraded rangelands at SabzKouh and Boroujen sites seem to recover rather quickly from long-term overgrazing with a proper grazing management, while rangeland ecosystems at Sheida site need a much longer period for steady-state conditions and for improvements in soil quality and fertility after long-term soil degradation and disturbance.

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Non-exchangeable potassium (NEK) release is necessary to supply potassium for plant in different soils. A few studies on the NEK release have been done in soils and particularly on its components. This study was intended to investigate the NEK release from soil and the components of clay and silt through successive extractions with oxalic acid (0.01 M) over a period of 1844 (h) in 4 soil series of Golestan province. The amount of NEK release from whole soil, silt and clay fractions after 1844 (h) were 242 to 450, 380 to 550 and 105 to 199 mg kg-1, respectively. The cumulative rates of NEK release after 1844 (h) were well described by simplified Ellovich, parabolic diffusion and power function equations. The rate of K release was high initially, and then decreased gradually in all soils and in their silt and clay fractions. The amount of released NEK (with high rate) consisted of lower percentage of total NEK, but in spite of less amount, this K form plays a vital role in K dynamic and soil fertility.

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This study was carried out to investigate zinc (Zn) and cadmium (Cd) concentration in paddy soil and rice grain produced in central and southwest Iran in relation to soil and plant factors, and their intake in peoples diet was also assessed. Rice crops and associated surface soils (0-30 cm) were collected from 136 fields in Isfahan, Fars and Khuzestan provinces. The result, showed the DTPA-Zn concentration in more than 50% of paddy soils was less than its critical deficiency concentration (2 mg kg-1). The grain Zn concentration in more than 54% of the rice samples was less than 20 mg kg-1. The measured Cd concentrations in paddy soils and edible part of rice exceeded the world health organization (WHO) value in more than 12% of the samples. By considering the average daily rice consumption of 110 g per capita, the Zn intake from rice consumption was estimated about 10% needed for female and male adult. Diet intake analysis did not indicate any excessive dietary intake of Cd when Cd mean of concentrations in rice grain was 0.04 mg/kg, but based on the results of risk analysis, it is more than safely level for contaminated rice.

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Direct measurement of soil hydraulic characteristics is costly and time-consuming. Also, the method is partly unreliable due to soil heterogeneity and laboratory errors. Instead, soil hydraulic characteristics can be predicted using readily available data such as soil texture and bulk density using pedotransfer functions (PTFs). Artificial neural networks (ANNs) and statistical regression are two methods which are used to develop PTFs. In this study, the multi-layer perceptron (MLP) neural network and backward and stepwise regression models were used to estimate saturated hydraulic conductivity using some soil characteristics including the percentage of particle size distribution, porosity, and bulk density. Data of 125 soil profiles were collected from the reports of basic soil science and land reclamation studies conducted by Khuzestan Water and Power Organization. The results showed that MLP neural network having Bayesian training algorithm with the greater coefficient of determination (R2=0.65) and the lower error (RMSE =0.04) had better performance than multiple linear regression model in predicting saturated hydraulic conductivity.

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This study was conducted to study and compare the effects of different tillage systems on soil physical properties and wheat yield in dryland conditions. The experiment was carried out in Maragheh Dryland Research Station with 5 treatments and 4 replications based on RCBD for 3 years (2001-2003). The results showed that difference between the treatments in terms of wheat yield was significant, and stubble chopping and chisel plow tillage in fall + sweep in spring + seed drill planting had the maximum yield (i.e. 1452 kg/ha), lower value for yield (1.077kg/ha) blonged to T1 treatment. Also the results showed that spike/plant and spike length were the main characters in yield increase. For the soil bulk density and water content, the difference between treatments was significant and in planting and flowering stages stubble chopping and chisel plow in fall + sweep in spring + planting by seed drill had the highest soil water content and the lowest bulk density

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This study was conducted to investigate the effect of water salinity and sodicity on pore size distribution and plant-available water of two clay and sandy clay loam calcareous soils. All combinations of water EC values of 0.5, 2, 4 and 8 dS m-1 and SAR values of 1, 5, 13 and 18 (in total 16 solutions) were used to wet and dry the soil samples for five cycles. Then, water retention of the soil cores was measured at matric suctions of 0 (θs), 10 (θ10) 100 or 300 cm (θFC) and 15000 cm (θPWP). The following quantities were calculated: the difference between θ100 or θ300 and θ15000 considered as available water contrent, the θs and θ10 as macrorosity, the θ10 and θ100 as mesoporosity, and the θ100 as microrosity. The initial porosity of both soils was similar, but the greater values of pore indices and θFC, θPWP and AWC were measured in the clay soil due to clay swelling. As water EC increased, mesopores were destructed and altered to macropores and micropores. Salinity altered the mesopores into macropores due to contraction of diffuse double layer and particle’s flocculation and consequently decreased the θFC, and created new micropores which were responsible for the higher value of θPWP. These trends ultimately diminished the AWC. As water SAR increased, mesopores were destructed and altered to micropores but it did not significantly affect the macropores. With increment of SAR, both θFC and θPWP increased due to structural distruption clay swelling and dispersion resulting in increased adsorptive and interlayer surfaces. The increasing effect of SAR on θPWP was greater and more distinct so that AWC was reduced. As a result, high values of SAR of irrigation water decreased the soil available water to plants besides its toxicity and hazardous effect on plants. With increment of irrigation water salinity, the destructive impacts of SAR diminished. The influence of water quality on water retention was pronounced for the clay soil.‎